Just after restarted the Primary PXC node, another node crashed a few minutes after. Here is crash log 15:30:35 UTC - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. Please help us make Percona XtraDB Cluster better by reporting any bugs at https://bugs.launchpad.net/percona-xtradb-cluster key_buffer_size=134217728 read_buffer_size=131072 max_used_connections=150 max_threads=502 thread_count=59 connection_count=57 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 331448 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x7f82081da690 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 7f8228e8fe50 thread_stack 0x1000000 /usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x8ccd9e] /usr/sbin/mysqld(handle_fatal_signal+0x36c)[0x6828dc] /lib/x86_64-linux-gnu/libpthread.so.0(+0xf0a0)[0x7f833465c0a0] /lib/x86_64-linux-gnu/libc.so.6(+0x78a8e)[0x7f83328dca8e] /lib/x86_64-linux-gnu/libc.so.6(__libc_malloc+0x70)[0x7f83328dea70] /usr/sbin/mysqld(my_malloc+0x32)[0x8c8bc2] /usr/sbin/mysqld(alloc_root+0x8c)[0x8c4b9c] /usr/sbin/mysqld[0x82e8dd] /usr/sbin/mysqld[0x82fa05] /usr/sbin/mysqld[0x83a0bc] /usr/sbin/mysqld(_ZN4JOIN8optimizeEv+0x60c)[0x83c0bc] /usr/sbin/mysqld(_Z12mysql_selectP3THDP10TABLE_LISTjR4ListI4ItemEPS4_P10SQL_I_ListI8st_orderESB_S7_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x21c)[0x71e5fc] /usr/sbin/mysqld(_Z13handle_selectP3THDP13select_resultm+0x175)[0x71e8f5] /usr/sbin/mysqld[0x59a85f] /usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0xb60)[0x6f8810] /usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x5c8)[0x6fd7f8] /usr/sbin/mysqld[0x6fd8f2] /usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1076)[0x6fef36] /usr/sbin/mysqld(_Z10do_commandP3THD+0x202)[0x6ffbe2] /usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x2ad)[0x6d11dd] /usr/sbin/mysqld(handle_one_connection+0x42)[0x6d1262] /usr/sbin/mysqld(pfs_spawn_thread+0x140)[0xb195d0] /lib/x86_64-linux-gnu/libpthread.so.0(+0x6b50)[0x7f8334653b50] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f833293f95d] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (7f81e03104d0): is an invalid pointer Connection ID (thread ID): 2459594 Status: NOT_KILLED You may download the Percona XtraDB Cluster operations manual by visiting http://www.percona.com/software/percona-xtradb-cluster/. You may find information in the manual which will help you identify the cause of the crash. 150404 17:30:35 mysqld_safe Number of processes running now: 0 150404 17:30:35 mysqld_safe WSREP: not restarting wsrep node automatically 150404 17:30:35 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended